The dramatic increase in unsolicited emails, commonly referred to as spam, has led business emailers to develop a number of mechanisms aimed at increasing the likelihood that emails will reach and be read by the intended recipients. One such mechanism is to create and maintain opt-in email lists, wherein potential recipients are able to affirmatively choose to be included on an email list of a business emailer and receive emails from that emailer. However, even in situations where a recipient has opted-in to receive emails from a specific emailer, it is sometimes difficult for the recipient to recognize an email, such as a marketing email, sent from that emailer (as distinguished from unwanted spam). As a result, the recipient may inadvertently ignore and/or delete an email that came from the emailer even though the recipient had previously opted-in to receive such emails. In addition, unscrupulous emailers may use the process wherein a previously opted-in recipient chooses instead to now opt-out as a sign that the email address of that recipient is live and in use, and may therefore increase the volume of unwanted emails to that address. Thus, there is a need for an opt-in email system in which a recipient that has opted in to an email list can recognize and trust that an email has actually come from the desired emailer (i.e., the one that they opted-in to receive email from) and which ensures that emails are no longer sent once a recipient has decided to opt-out of the email list.